66256972566 has 16 divisors (see below), whose sum is σ = 132649590384. Its totient is φ = 22063049984.

The previous prime is 66256972543. The next prime is 66256972679. The reversal of 66256972566 is 66527965266.

It is a happy number.

It is a super-2 number, since 2×66256972566² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5645535 + ... + 5657258.

It is an arithmetic number, because the mean of its divisors is an integer number (8290599399).

Almost surely, 2^66256972566 is an apocalyptic number.

66256972566 is an abundant number, since it is smaller than the sum of its proper divisors (66392617818).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66256972566 is a wasteful number, since it uses less digits than its factorization.

66256972566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11303775.

The product of its digits is 48988800, while the sum is 60.

The spelling of 66256972566 in words is "sixty-six billion, two hundred fifty-six million, nine hundred seventy-two thousand, five hundred sixty-six".